2577 Dysdiadochokinesia, Ataxia, and Anemia: A Sign of Intraluminal Malignant Mesothelioma in the Small Bowel?

Abstract

INTRODUCTION: Malignant mesothelioma (MM) is a rare cancer of the serosal membranes, the pleura and peritoneum, and causes significant morbidity and mortality. While implants of the bowel wall are common, only two case reports on intraluminal involvement exist. We present a case of an elderly male with dysdiadochokinesia found to have abdominal lymphadenopathy, and a jejunal mass from peritoneal mesothelioma (PM). CASE DESCRIPTION/METHODS: An 87 year-old male with a family history (FH) of colon cancer in one first-degree relative presented with one month of unintentional weight loss, gait instability, and trouble performing alternating movements. Two months prior to admission, evaluation included a negative MRI of the brain but positive CSF analysis for neuron-restricted autoantibody treated empirically with five days of intravenous immunoglobulin (IVIG) and three days of pulse dose steroids. Physical examination was notable for ataxia and dysdiadochokinesia and a benign abdominal exam. He had normal electrolytes and liver chemistries, but was anemic. PET/CT revealed intensely FDG-avid abdominal and mesenteric lymph nodes, one inseparable from the small bowel (Figures 1 and 2). Lymph nodes were not accessible by IR-guided biopsy, so he underwent push enteroscopy and colonoscopy, in light of his FH, to evaluate for anemia. A large, oozing ulcerated mass was found in the jejunum and biopsied (Figure 3). Immunostaining was positive for cytokeratin, CK7, WT1, and calretinin consistent with PM. His neurologic decline was then linked to PNS secondary to PM. He was discharged with plans for carboplatin therapy. DISCUSSION: MM is strongly associated with asbestos exposure, and is four to five times more prevalent in men than women. PM limited to the small bowel is exceedingly rare. Only one previous case report describes a mass spanning the entire small bowel, identified as mucin-positive epithelial mesothelioma. PNS affects 1 in 10,000 patients with cancer; more than 85% of cases are linked to gynecologic and breast cancers causing cerebellar dysfunction via purkinje cell destruction by anti-Yo antibody (Ab). Two cases of PM associated PNS with anti-Yo Ab in the CSF have been reported; one was treated with IVIG and high dose steroids. The treatment of PM is key to stabilizing neurologic symptoms, such as dysdiadochokinesia. The prognosis of PM and associated PNS remains poor. Anemia with cerebellar symptoms should trigger a search for malignancy and rarer causes such as PM.